 /*******************************************************************************
  * Copyright (c) 2000, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.texteditor.quickdiff;


 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.source.ILineDiffInfo;
 import org.eclipse.jface.text.source.ILineDiffer;

 import org.eclipse.ui.internal.texteditor.NLSUtility;
 import org.eclipse.ui.texteditor.ITextEditor;

 /**
  * Action that will restore a block of deleted lines at the current caret position in an editor.
  *
  * @since 3.0
  */
 public class RestoreAction extends QuickDiffRestoreAction {
     /** Resource key prefix. */
     private static final String PREFIX= "RestoreAction."; //$NON-NLS-1$

     /** The line to be restored. Set in <code>update()</code>. */
     private int fLine;

     /**
      * Creates a new instance.
      *
      * @param editor the editor this action belongs to
      * @param isRulerAction <code>true</code> if this is a ruler action
      */
     public RestoreAction(ITextEditor editor, boolean isRulerAction) {
         super(PREFIX, editor, isRulerAction);
     }

     /*
      * @see org.eclipse.ui.internal.texteditor.quickdiff.QuickDiffRestoreAction#computeEnablement()
      */
     public boolean computeEnablement() {
         if (!super.computeEnablement())
             return false;

         fLine= getLastLine();
         if (fLine == -1)
             return false;
         ILineDiffer differ= getDiffer();
         if (differ == null)
             return false;
         ILineDiffInfo info= differ.getLineInfo(fLine);
         if (info == null || (info.getRemovedLinesAbove() <= 0 && info.getRemovedLinesBelow() <= 0))
             return false;

         if (info.getRemovedLinesBelow() == 0) {
             fLine--;
         } else if (info.getRemovedLinesAbove() != 0) {
             // take the line below
 }
         info= differ.getLineInfo(fLine);
         if (info == null)
             return false;
         if (info.getRemovedLinesBelow() == 1)
             setText(QuickDiffMessages.RestoreAction_label);
         else
             setText(NLSUtility.format(QuickDiffMessages.RestoreAction_multiple_label, String.valueOf(info.getRemovedLinesBelow())));
         return true;
     }

     /*
      * @see org.eclipse.ui.internal.editors.quickdiff.QuickDiffRestoreAction#runCompoundChange()
      */
     public void runCompoundChange() {
         if (!isEnabled())
             return;
         ILineDiffer differ= getDiffer();
         if (differ != null) {
             try {
                 differ.restoreAfterLine(fLine);
             } catch (BadLocationException e) {
                 setStatus(e.getMessage());
             }
         }
     }
 }

